Motor vehicle seat restraint systems typically include a multi-point restraint harness, made up of one or more restraint webs, coupled thereto. Some such restraint systems may further include a device or devices for pre-tensioning the restraint harness, i.e., for tightening the restraint harness about the seat occupant, under certain operating conditions such as during or in advance of a vehicle rollover and/or a vehicle impact event. In embodiments in which the motor vehicle seat is a suspension seat, i.e., a motor vehicle seat in which an occupant seat portion is suspended above a seat base by a suspension structure extending therebetween, such a device or devices may alternatively or additionally operate to pull the suspended seat portion downwardly toward the seat base under such conditions.